Swallow Medaka

Swallow Medaka key facts

Care level

Intermediate

Lifespan

2-3 years

Size

Up to about 4cm SL

Temperature

18〜28℃

Diet

Prepared medaka food, green water

Lighting

The protruding rays read most clearly from the side, so a tank viewed horizontally suits this trait. Outdoors, summer sun raises water temperature sharply, so shade half the container with something such as a reed screen.

Diet & Nutrition

Commercial prepared medaka food is the staple, given in an amount finished within a few minutes. Leftovers decay and foul the water, so adjust the quantity. Green water rich in phytoplankton suits fry rearing.

Water Temperature & Quality

Slightly acidic to slightly alkaline water is considered ideal, and the water drifts toward acidic as keeping continues. Around one water change per week is the guideline, and because sudden shifts in temperature or pH cause stress, acclimatise new fish by floating the bag. FishBase records the wild water chemistry of this species as pH 7.0-8.0 and hardness 9-19 dH.

Tank Mates & Compatibility

Elongated fins are easily damaged by obstructions or crowding, so keep the container uncluttered and the stocking light. A peaceful schooling fish, normally kept as a group of the same variety. One litre of water per fish is the guideline against overcrowding; overstocking causes poor growth, reduced breeding, oxygen shortage and water fouling.

Breeding

Outdoors the spawning season runs from about April to October, once water reaches 18C or above with 12-13 hours of daylight. For year-round indoor breeding, 25-28C water and over 13 hours of lighting are the guideline. Eggs hatch at a cumulative 250 degree-days, about 10 days at 25C.

Health & Notes

The protruding rays are thin and damage easily, so keep sharp-edged obstacles out of the container. The Medaka Web Encyclopedia warns against confusing the trait with hirenaga and merah: hirenaga elongates the whole fin including the membrane, while swallow protrudes only part of the rays. Outdoors the fish become inactive and overwinter near the bottom as water cools, resuming activity in spring once daytime water exceeds 10C. A 0.3-0.5% salt bath is used for ailing fish, with water raised to no more than about 28C.

About Swallow Medaka

Swallow Medaka is a fancy medaka with elongated fin rays, developed in 2012 and also known as "Fuga." Reaching about 4cm, it's a fin-focused variety best suited to intermediate keepers.

7 things to know before welcoming a Swallow Medaka

1. 1Fin Length Varies by Fish

   The number and length of elongated fin rays vary widely from one Swallow Medaka to another. Even siblings from the same parents can turn out differently, so watching each fish develop its own look is part of the fun.

2. 2Also Known as "Fuga"

   The Japan Medaka Association classifies this variety under the name "Fuga." Since it goes by more than one name, it helps to recognize both when researching or looking into this variety.

3. 3Fins Develop Over Time

   The elongated fins start to appear gradually from the fry stage and become more pronounced as the fish matures. It takes patience to see how a given fish's fins will ultimately turn out.

4. 4Swimming Can Be Affected

   Fish with especially long fins may swim somewhat less nimbly than standard medaka. Avoid strong filter currents and provide a calm environment where they can move around comfortably.

5. 5Keep Water Quality Consistent

   Maintaining beautiful fins depends on consistent water quality care. Regular water changes, avoiding sharp decorations, and not overcrowding the tank all help keep the fins in good condition.

6. 6Choose Tankmates Carefully

   Long, trailing fins can get nipped if kept with aggressive or much larger fish. Stick to calm, peaceful tankmates and avoid species known to nip at fins.

7. 7Best Suited to Intermediate Keepers

   Swallow Medaka is generally considered an intermediate-level variety. Basic care is similar to standard medaka, but keeping an eye on fin condition and managing water quality and tankmates well will help the fish show their best form over time.

Frequently asked questions about Swallow Medaka

Q.Does the Swallow Medaka's fins always grow long?

A.Not necessarily — the degree of fin elongation varies a lot between individuals, and some fish grow less than expected. How many fin rays extend and how long they get often isn't clear until the fish matures.

Q.Is "Fuga" the same variety as Swallow Medaka?

A.Yes, the Japan Medaka Association classifies Swallow Medaka under the name "Fuga," referring to the same trait. Regardless of which name is used, it's the same underlying variety.

Q.Can it be kept with other medaka?

A.It can be kept with calm, peaceful varieties, but it's safer to avoid fish known to nip at long fins. Watch how the fish interact closely whenever keeping them together.

Q.How large does it grow as an adult?

A.It reaches a standard body length of about 4cm at most. Including the fins it may look larger, but the body size itself is similar to standard medaka.

Q.Is this variety suitable for beginners?

A.This variety is generally considered better suited to intermediate keepers. It's best to get comfortable with basic medaka care first, then take on this variety with attentive observation of fin condition.

Useful tools for Swallow Medaka care

Learn more about Swallow Medaka in the encyclopedia

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